The present disclosure generally relates to head-mounted displays (HMDs), and specifically to determining interpupillary distance and/or eye relief of a user wearing a HMD.
HMDs include a display and optics elements that project the image from the display to the eyes of a user wearing the HMD. The image is projected to an “eye box” for each eye of the user, which is a volume of space in which the user's eyes must be located to view the image correctly. Variations in the shapes of human faces present a challenge for designing HMDs. Accordingly, conventional HMDs are designed to accommodate a range of user anatomies, while sacrificing ideal eye box placement for all users. As a result, variations in the interpupillary distance (i.e., the distance between a person's eyes) and the eye relief (i.e., a depth of the user's eyes relative to other facial features of the user, particularly facial features on which the HMD rests) may result in a user experiencing optical distortions caused by one or both eyes being outside the eye box.